I had a chance to A/B my Pignose Dumble clone with a Fuchs SF Bassman yesterday with a variety of cabs. While I was pleased to hear some nice similarities between the amps, the real kicker was pulling out the Sovteks and throwing in a set of TAD 6L6s. I know there's been a lot of hype thrown around about tubes, but the difference with the TADs was pretty astounding. All of the harshness that was driving me crazy was GONE! Smooth crunch, chunky bass, and very sweet top end. I really hated to have to pull out the TADs and put the Sovteks back in, but I've got a set on order so it won't be long.